We proposed an optical magnetic field sensor with the temperature correction capability, which is based on an optical microfiber taper (OMT) integrated with magnetic fluid. The OMT is fabricated simply by fused tapering and then sealed into a capillary tube filled with magnetic fluid. The sensor is highly sensitive to magnetic field with the sensitivity of 0.171 nm/Oe in the range of 20-70 Oe at room temperature 25 ---. Moreover, there is a linear relationship between the wavelength shift and temperature in range of 30-80---, and a sensitivity of -0.587 nm/--- has been achieved. Based on these experiments, we provided a sensitivity matrix to correct the errors caused by temperature in order to measure magnetic field more accurately.